The Hearing Research Center (HRC) at Boston University (B.U.) was established in 1995 for the development and dissemination of knowledge that will improve the nation's auditory health and allow the fullest utilization of the sense of hearing. The HRC includes faculty from across the colleges of the university and provides a stimulus for interactions across research techniques and fields. Starting in the year 2000, a P30 Core Center grant has supported two cores, a Sound-Field Laboratory Core and an Engineering Support Core. This proposal requests the renewal of this grant, which provides critical assistance for sharing facilities, support personnel, equipment, and expertise; forthe development of mechanisms for sharing data and models across laboratories; and for the promotion of scientific interactions among faculty in different laboratories at B.U. and at other institutions in the general region. The requested core support will promote integrative, multidisciplinary collaborations involving auditory physiology, psychoacoustlcs, and computational modeling. The sound-field laboratory provides a controlled, adjustably reverberant environment, allows common setups and stimuli in acoustic and psychoacoustic measurements, and provides support for acoustic and psychoacoustic measurements, including assistance with human subject recruitment, protection, and documentation. The engineering support core allows the archiving and analysis of data from groups working in different disciplines, promotes the integration of modeling efforts that are distributed across different laboratories and at different levels ofthe auditory pathway, and provides general computer and technical support to all investigators and laboratories in the Core Center. These cores and the support they provide are designed specifically to use resources efficiently, to promote collaboration, and to develop resources of general use to the hearing research community.